Under oxygen transfer rates (OTR), from 10 to 30 mmol. l –1 h , Candida boidinii NRRL Y-17213 exhibited both NADH and NADPH linked D-xylose reductase activities with the former being higher. Xylitol dehydrogenase was mainly NAD dependent. Maximum xylitol production was attained at OTR of 14 mmol. l h . Ethanol, glycerol and ribitol were also produced. A correlation between xylitol accumulation,...

Xylose reductase (XR) is the first enzyme in D: -xylose metabolism, catalyzing the reduction of D: -xylose to xylitol. Formation of XR in the yeast Candida tropicalis is significantly repressed in cells grown on medium that contains glucose as carbon and energy source, because of the repressive effect of glucose. This is one reason why glucose is not a suitable co-substrate for cell growth in i...

Sugarcane straw has become an available lignocellulosic biomass since the progressive introduction of the non-burning harvest in Brazil. Besides keeping this biomass in the field, it can be used as a feedstock in thermochemical or biochemical conversion processes. This makes feasible its incorporation in a biorefinery, whose economic profitability could be supported by integrated production of ...

Immobilized Candida tropicalis cells in freeze dried calcium alginate beads were used for production of xylitol from lignocellulosic waste like corn cob hydrolysate without any detoxification and sterilization of media. Media components for xylitol fermentation were screened by statistical methods. Urea, KH2PO4 and initial pH were identified as significant variables by Plackett-Burman (PB) desi...

Xylitol has most commonly been studied in chewing gum, with just a few studies looking at its action in toothpaste, mouthrinse, or tablets. Most of the studies have been done in children, with fewer studies in adults. Very little has been done to look at effects of xylitol in patients over 65 or root surfaces (Makinen, et.al 1995b). There is an abundance of available evidence on xylitol’s actio...

Xylitol is a natural sweetener used commercially as a substitute for sucrose, mainly by its low-calorie and anticariogenic properties. Moreover, its metabolism is independent of insulin, which can be used by people with diabetes and obesity problems. Currently, xylitol is produced by catalytic hydrogenation of D-xylose, a costly process because it requires highly purified xylose syrup. As an al...

Wheat straw hemicellulosic hydrolysate was used for xylitol bioproduction. The use of a xylose-containing medium to grow the inoculum did not favor the production of xylitol in the hydrolysate, which was submitted to a previous detoxification treatment with 2.5% activated charcoal for optimized removal of inhibitory compounds.

Anaerobic glucose oxidation was coupled to xylose reduction in a nonfermentative Escherichia coli strain expressing NADPH-dependent xylose reductase. Xylitol production serves as the primary means of NAD(P)(+) regeneration, as glucose is converted primarily to acetate and CO(2). The membrane-bound transhydrogenase PntAB is required to achieve the maximum theoretical yield of four moles of xylit...

1. Loading the isolated perfused liver from well-fed rats with xylitol (20mm) caused a depletion of adenine nucleotides and P(i) and an accumulation of alpha-glycerophosphate. The ATP content fell to 66% of the control value after 10min and to 32% after 80min. The ADP and AMP contents also fell. After 80min 63% of the total adenine nucleotides and 59% of the P(i) had been lost. 2. The alpha-gly...